7 ms·

Kind of related: does anyone else notice how long it takes to change channels on the TV these days? It used to be instantaneous when cable first came out and

• taeric 7y ago
  It is interesting to see just how much more information is in a second of video than it used to be. That said, I'm not sure that counts for the latency by itself. Pretty sure it doesn't. :(
• wbl 7y ago
  It takes time to pick up the MPEG2 scheme and start decoding.
  • java-man 7y ago
    all they need is to create to a low rate channel with slowly updating snapshots of all the programs being transmitted. i don't know anyone who does that, but it is damn trivial. (former middleware engineer)
    • wolfgke 7y ago
      > all they need is to create to a low rate channel with slowly updating snapshots of all the programs being transmitted. > i don't know anyone who does that, but it is damn trivial. Getting this standardized in an international standard is far from trivial.
      • java-man 7y ago
        "they" usually write requirements for set top middleware and control the broadcast. the problem, i think, is not that it is difficult (Musk launched a massive electric car company and spacecraft to ISS in the relevant time frame), but that "they" don't care about the users. pretty much anything cable and satellite tv companies do is against the user. there is very little (if any) innovation in the industry, and that's why they will eventually die.
      • Pelam 7y ago
        You may well be hitting a deeper point here. Many of the strongest AND weakest consumer technology experiences are influenced by standards in some way. Positive Examples: pluging in an usb headset, electrical sockets, sms. Negative examples: Trying to hook up your laptop in a random conference room, transferring a large file locally between 2 devices from different vendors. Maybe with ever increasing conplexity and capability the annoyances fall between industry actors and solutions would need first multiple parties acknowledging the problem followed by succesful coordination.
    • jaywalk 7y ago
      The Ericsson MediaRoom IPTV platform (used by AT&T Uverse in the US) does something similar to this, but it's only used to show a small window to preview the highlighted channel while you're scanning the guide.
• rohan1024 7y ago
  Also, TVs kinda started having a black screen in between switching of channels. At night that becomes incredibly uneasy for eyes.
• ryanianian 7y ago
  My favorite "the world is terrible" curmudgeon observation is how awful hotel TVs (and hotel TV remotes) are. Every single hotel room TV I've had the displeasure of using in the last N years takes more than 20 seconds to turn on after multiple button-presses, starts out on a terrible in-house channel at high volume regardless of the last-watched channel+volume, takes multiple seconds to change channels, and has no real TV guide option to let you see what's on. This plus HDMI ports are regularly inaccessible and it's nearly impossible to use streaming sticks (roku) due to web-based wifi portals that only work half the time if you have an ad-blocker enabled.
  • arethuza 7y ago
    Careful what you wish for - many years ago I worked for an interactive TV company that focused on the hospitality market. One large chain of hotels seriously asked if we could do a remote control with three additional large buttons at the top for "Beer", "Burger" and "Porn". Turns out getting like that manufactured in the quantities we were looking at is a nightmare - so it didn't happen. Edit: Clearly it would have been easier to have one button for "Beer, burger and porn" - but that has only occurred to me now.
    • javajosh 7y ago
      Sounds like a legit app, though.
  • logfromblammo 7y ago
    The usual problem I have is that I need to switch to DHCP based DNS to register my MAC address to the room number, then switch back so the hotel can't screw with my DNS lookups. It might not be your ad-blocker or script-blocker; it might be your DNS settings.
  • papito 7y ago
    Hotel remotes. You all triple-sanitize them, right? And then burn them....
    • 7y ago
• wolfgke 7y ago
  The central reason is that modern video codecs use I-frames and P-frames (sometimes also B-frames; even though as far as I am aware, these are not used for TV broadcasts); see https://en.wikipedia.org/w/index.php?title=Video_compression_picture_types&oldid=916270429 https://en.wikipedia.org/w/index.php?title=Video_compression... I-frames are only sent, say, once or twice a second. When a channel is switched, the TV has to wait for the next I-frame, since P-frames (and B-frames) only encode the difference to the previous I-frame (or to the previous and next I-frame in the case of B-frames). If you are aware of a possibility for efficient video compression that avoids this problem, tell the HN audience; the really smart people who developed the video codecs apparently have not found a solution for this. ;-) Otherwise complain to your cable provider that they do not send more I-frames to decrease the time to switch between channels (which would increase the necessary bandwidth).
  • jasonjayr 7y ago
    Cache the most recent iframe on the network and have the STB pull + display the cached iframe till it catches up? This would enable fast channel scanning/flipping at the very least ...
    • wmf 7y ago
      IIRC Microsoft did this in their IPTV platform.
  • fortran77 7y ago
    No. It's not a codec problem. They can leave it on the last decoded frame and fade it nicely to, say, the average color for the 1 second without going to black, and you don't have to be a super decoder genius to implement something that's a little less aesthetically jarring.
    • wolfgke 7y ago
      joncrane was complaining about the time to change channels. This approach does nothing to decrease this time.
• athenot 7y ago
  When working on digital settop boxes a decade or 2 ago, channel change latency was one of the toughest problems. Eventually we (collectively, the whole industry) gave up and settled for 1 second as acceptable. Channel surfing quietly went away. When your i-frame only comes so often, there's not a whole lot you can do. Nowadays, that problem is solved by reducing actual live content to a strict minimum; everything else can be on-demand.
  • criddell 7y ago
    These days they should be able to guess what 20 channels you might change to and start recording those in the background. I've always suspected the reason it's slow is because you press the remote button, the DVR sends that to the provider, the provider has to verify that you can do what you are asking it to do, then a response comes, then the change can start.
    • jaywalk 7y ago
      Nope, the STB has everything it needs to decrypt the channels you have access to. Tuning live TV channels happens 100% on the box. The only exception (a technology called Switched Digital Video) is just a way to save bandwidth on the cable, nothing to do with conditional access.
      • criddell 7y ago
        If I unplug my internet connection, my box won't let me do much at all. If I press pause or fast forward it just tells me the operation isn't authorized.
        • jaywalk 7y ago
          That's a weird system, certainly not the standard way of doing things on a traditional cable TV system.
          • criddell 7y ago
• fortran77 7y ago
  Yes. They can fade out the old screen with "snow" until the next MPEG stream starts to decode.
• BubRoss 7y ago
  It depends on the TV or tuner box. Some are very fast and some are very slow. It is something you have to test before buying if you can.
  • jeffhuys 7y ago
    Yeah, it sucks though that most tv providers supply the lowest-specced box they can provide. For my parents it was bad when they bought a 4k television, and the box "supports" that, though since some firmware update it starts lagging every 20secs. Dropped frames and the usual video-"smudge". I hope they get a (FREE) update soon. Because this is just a broken promise. And I'm not even talking about the Netflix "app" that's on there. Holy s#!t that's slow. Or the TV-guide. They now resort to teletext because that's much faster... I mean...
• Causality1 7y ago
  It's patently absurd that a modern cable box chugs just when flipping through the channel guide. The provider has control over the software and the hardware so it should be butter smooth all the time.
  • magduf 7y ago
    Doing that would take extra work, and cost more money. Why should they bother, when the dinosaurs who still watch cable TV aren't going to pay them any more for this butter-smooth experience? The people who care about such things have all moved to on-demand streaming services.
• agumonkey 7y ago
  Analog TV were real time at the speed of electrons minus some layers of inertia (capacitance say). Nowadays there's many layers of various quality, and software reactivity is a factor of so many things.
  • Koshkin 7y ago
    To be more accurate, the speed with which electrons move through the wire is rather low (which does not matter, of course, because the signals are carried by the electromagnetic forces which propagate very quickly).
• mrlala 7y ago
  This I do agree with. I haven't had cable for years and years, but when I'm at someone elses house I am baffled how insanely slow it is. That would drive me NUTS on a day-to-day basis.
• doctor_m 7y ago
  Modern cable systems are more akin to satellite broadcast systems than they are to the terrestrial broadcast systems of yore. There's an order of magnitude more content on cable these days. When you tune a channel now, instead of simply tuning to a frequency and demodulating the signal, content is spread across many frequencies, each of which carries a QAM-modulated MPEG transport stream that carries many programs. It takes longer to tune QAM than baseband analog or even PSK. So the physical frequency change takes longer than it used to do. Once frequency is tuned, decoder may need to check provisioning in order to be able to decrypt whatever program you've requested, so that adds to the time it takes.
• post_break 7y ago
  I don't know who can afford cable any more to be honest. The only people I know who pay for cable are in the 45+ age range and they only use it because they just leave it on 24x7 or to watch the weather.
• hateful 7y ago
  I remember when this happened, when it went "digital" and I know why it takes a second to switch channels, but it ruined the experience for me. While, at the time there was ways to watch video on the computer or from a DVD or VHS, I still liked to "channel surf" every once in a while. But that requires switching channels fast for an random amount of time based upon what was on and how long it took your brain in that moment to absorb it. And sometimes you'd stop and go back. But with digital, most of the time the load time was longer than the time I'd be on that channel in the first place. It'd take minutes to go through 10 channels as opposed to seconds. Channel surfing was its own activity for me back then - and it was ruined. Nowadays there's youtube - but it's hardly the same thing.
• ajmurmann 7y ago
  It's not only switching channels, even just turning the thing on. Also switching between inputs takes a long time, a large part of which is spend in the menu. The only thing I ever do is switch between AppleTV and PS4 and adjust volume because the PS4 is orders of magnitude louder than the AppleTV, yet so of that always feels super clunky if I have to use the TV remote.
• OGWhales 7y ago
  Also navigating through the "guide" is simply horrendous.
• m463 7y ago
  The problem is that (mpeg video frames, mpeg audio frames, streaming latency, hdmi decoding, etc...) all introduce a delay for reasons. The answer: put an ad in there.